HOENGGYE, South Korea — This once-sleepy village is buzzing with activity. With less than 100 days until South Korea’s PyeongChang Winter Olympics are due to start, the builders are in the final sprint.

Nearby, the Olympic Stadium is nearing completion. Roads are being widened to deal with the expected surge in visitors, while landscapers plant flowers and trees along the sidewalks in a traditionally rustic area. In a new building serving as a planning hub, young Koreans and foreign guests grab coffee and snacks at a McDonald’s to keep up with the frantic pace.

Among locals, there is excitement in the air — but also some serious nerves.

Cho Hyun-sab moved to the area from the Seoul suburbs especially for the Games. Just over a week ago, he opened a dumpling restaurant in anticipation of the crowds. He hopes to start a franchise. “This is branch number one,” Cho said while attending to several steaming trays.

However, the 32-year-old is careful not to be too optimistic. He suspects the Games may have been overhyped in South Korea. “The general expectations are so high,” he said. “I don’t want to be disappointed.”

Cho is not the only one with concerns. For all the excitement, there are worrying signs that the PyeongChang Games are running into trouble. Ticket sales have been low — 35 percent of what was hoped for at this point. And a large amount of work needs to be done.

These concerns are not unusual for an Olympic host. But the PyeongChang Games also have a more unique issue: a nuclear-weapons-minded North Korea that sits about 50 miles from the Olympic venues.

When South Korea won the contest to host the 2018 Winter Olympics seven years ago, the North Korea factor looked like little more than an inconvenience. There was even serious talk of South Korea co-hosting the event with North Korea as a sign of goodwill.

Now, with just weeks to go until the event, North Korea could be a major problem for the PyeongChang Games. The North has made significant progress with weapons programs in recent months, testing missiles and conducting a huge underground nuclear bomb test in September despite international condemnation.

The circumstances have sparked some alarming talk among Olympic officials. In September, the French sports minister suggested that the country would keep its athletes at home if their safety could not be assured.

Last month, a British official told the BBC that the country had an evacuation plan for the Games and that “welfare” officers would be traveling with the athletes to “make sure that they feel entirely content.”

The North Korea issue also comes alongside other big problems that are unique to the PyeongChang Games, including the political scandal that led to this year’s impeachment of South Korea’s previous president and a diplomatic spat with China over the deployment of a U.S.-made missile defense system.

Worse still, the issues may affect not only the Olympics but tourism as a whole. The country’s central bank announced Sunday that the number of foreign visitors to South Korea plunged by almost a quarter in the first nine months of the year compared with 2016.

It is a worrying combination for organizers. South Korean President Moon Jae-in has tried to calm nerves, telling reporters at a New York event in September that “a successful hosting of the PyeongChang Games would erase worries over security and show the world regional peace and stability on the Korean Peninsula.”

Olympic organizers have tried their best to reassure potential visitors and take their minds off the threat from North Korea — even adding a capitalized “C” to the county’s Romanized name so it is not mistaken for the North Korean capital, Pyongyang.

They have held a number of Kpop-filled events this week to mark 100 days until the event, hoping to get potential ticket buyers interested.

But the situation is complex: In order to be reassuring, organizers often have to remind people of the very threat they want them to forget. Choi Moon-soon, governor of Gangwon province, which includes PyeongChang, has told the local news media that the worries could lead to the Games becoming a “global humiliation” for South Korea.

Some suggest that the risk of conflict with North Korea is overhyped. “People outside Korea are concerned about the North Korean threat, but there have been threats for many decades,” said Lee Kean-hee, 34, who runs a shop opposite the Olympic Stadium that sells the local specialty of dried pollock fish. “Koreans living here are not so concerned, so you don’t need to be, either.”

North Korea has made things difficult before for South Korea ahead of sporting events. A year before the 1988 Seoul Olympic Games, North Korean agents bombed a Korean Air flight, killing everyone on board. And during the 2002 World Cup, a North Korean warship opened fire on a South Korean patrol boat, leaving six soldiers dead.

However, experts say that any attack at the Games is unlikely. “I think the Olympics will be safe,” said Robert E. Kelly, an expert on North Korean security issues at Pusan National University.

Notably, two North Korean athletes — figure skaters Ryom Tae Ok and Kim Ju Sik — have qualified for the Games, and many hope they will serve as an insurance policy against any provocations. Sim Jae-kook, ­mayor of PyeongChang county, said that although it is unclear whether North Korea will participate in the Games, it has said it will send a team to the Pyeong­Chang Paralympics, which begin soon after.

Choi Kang, vice president of the Asan Institute for Policy Studies, a Seoul think tank, said that he did not expect any provocative actions during the Games but that North Korea may stage a missile test or atmospheric nuclear test in the coming months.

“Unfortunately, South Korean Olympic organizers cannot do much to prevent such things from happening,” Choi said.

Even if North Korea does not end up taking such a step, the Games could still be harmed by the impression it might do so. “I’m not surprised the ticket sales are low,” Pusan’s Kelly said. “North Korea generates a lot of unnecessary hysteria in the West.”

Sim, the mayor, noted that officials need to be prepared not only for North Korea but also for terrorist groups such as the Islamic State and disasters both natural and “artificial.”

“There will be a lot of soldiers everywhere — even up in the mountains — so we will be prepared perfectly,” Sim said.

But local officials are aware that they are in a race to finish the preparations.

“By this time, it’d be natural for all the venues and infrastructures to be complete,” said Lee Sung-han, chief secretary of PyeongChang county. In some areas, she said, people “might even wonder if this is the location for the Winter Olympics.”

For all the delays and uncertainty, Sim noted that a vast number of new roads have been built in this poor, rural county, and a high-speed train connection to Seoul is due to open within two months.

At an event in Seoul to promote the Games on Wednesday, many South Koreans said that they were hoping to attend the Olympics but had not yet bought tickets.

“The mood will pick up,” said Yeo Hee-sung, a 60-year-old retired civil servant. “South Koreans can get excited in a very short amount of time,” he noted, before pausing. “They can also cool down in a very short amount of time.”